Basic summary- Approx. 100 Miami-Dade County Public School principals are the sample in a longitudinal study of their instructional leadership behaviors as predictors for student achievement. Interestingly, coaching, evaluation and development of the instructional programs of the school are identified as predictors of student achievement growth. However, classroom walkthroughs negatively predict student achievement growth (especially in secondary schools). This, according to the study, is due to the lack of association of the walkthrough as part of the overall instructional program or school improvement strategy. Intersting. Evaluation as just a “to-do” activity has no power in improving anything really. But, read it yourself and conclude what you want.Study- Grissom, J. A., Loeb, S., & Master, B. (2013). Effective instructional time use for school leaders: Longitudinal evidence from observations of principals. Educational Researcher, 42 (8), 433-444. DOI: 10.3102/0013189X13510020